Tag Archives: Light

What do you do when you really don’t have much to tell on a subject, especially when you care a lot about it? You tell anecdotes and try to keep it interesting. Most neuroscience books these days tend to be packed with anecdotes that are weird, but on which there is no scientific consensus. The reader is left to his/her own devices on what to make of all the stories. This book is not much different. It starts with an admission that we know next to nothing about sleep – the activity that occupies 1/3rd of our lives.

The author sets off an a quest to discover more about his own sleep conditions and finds that he has fallen into a strange rabbit hole that exists just on the other side the pillow, and which most of are never aware of.

Once I started really thinking about sleep for the first time, the questions came in waves. Do men sleep differently than women? Why do we dream? Why is getting children to fall asleep one of the hardest parts of becoming a new parent, and is it this hard for everyone around the world? How come some people snore and others don’t? And what makes my body start sleepwalking, and why can’t I tell it to stop? Asking friends and family about sleep elicited a long string of “I don’t knows,” followed by looks of consternation, like the expressions you see on students who don’t know the answers to a pop quiz. Sleep, the universal element of our lives, was the great unknown. And frankly, that makes no sense.

A few take aways:

1. The Need for sleep:

Most of us will spend a full third of our lives asleep, and yet we don’t have the faintest idea of what it does for our bodies and our brains. Research labs offer surprisingly few answers. Sleep is one of the dirty little secrets of science. We don’t know about sleep, and the book opens with the most obvious question of all—why we, and every other animal, need to sleep in the first place.

Here we hear many horror stories of sleep-deprivation: Within the first twenty-four hours of sleep deprivation, the blood pressure starts to increase. Not long afterward, the metabolism levels go haywire, giving a person an uncontrollable craving for carbohydrates. The body temperature drops and the immune system gets weaker. If this goes on for too long, there is a good chance that the mind will turn against itself, making a person experience visions and hear phantom sounds akin to a bad acid trip. At the same time, the ability to make simple decisions or recall obvious facts drops off severely. It is bound to end in severe consequences – including death. It is a bizarre downward spiral that is all the more peculiar because it can be stopped completely, and all of its effects will vanish, simply by sleeping for a couple of hours.

2. The Amount of sleep:

Humans need roughly one hour of sleep for every two hours they are awake, and the body innately knows when this ratio becomes out of whack. Each hour of missed sleep one night will result in deeper sleep the next, until the body’s sleep debt is wiped clean.

3. The Stages of Sleep:

Researchers now say that sleep is made up of five distinct stages that the body cycles through over roughly ninety-minute periods. The first is so light that if you wake up from it, you might not realize that you have been sleeping. The second is marked by the appearance of sleep-specific brain waves that last only a few seconds at a time. If you reach this point in the cycle, you will know you have been sleeping when you wake up. This stage marks the last stop before your brain takes a long ride away from consciousness. Stages three and four are considered deep sleep. In three, the brain sends out long, rhythmic bursts called delta waves. Stage four is known as slow-wave sleep for the speed of its accompanying brain waves. The deepest form of sleep, this is the farthest that your brain travels from conscious thought. If you are woken up while in stage four, you will be disoriented, unable to answer basic questions, and want nothing more than to go back to sleep, a condition that researchers call sleep drunkenness. The final stage is REM sleep, so named because of the rapid movements of your eyes dancing against your eyelids. In this type of sleep, the brain is as active as it is when it is awake. This is when most dreams occur.

4. The Ideal Pattern of Sleep (that you are not following):

Natural light is the way to go. Artificial light messes up your sleep patterns and the body pays for it in the long run. Post-Edison world has come close to banishing the night, but our bodies still live in a world where sun is the only source of light, and have all sorts of troubles processing artificial light induced sleep patters. More and more health problems are being tied to unnatural sleep patterns and Light Pollution.

Example: Electric light at night disrupts your circadian clock, the name given to the natural rhythms that the human body developed over time. When you see enough bright light at night, your brain interprets this as sunlight because it doesn’t know any better. The lux scale, a measure of the brightness of light, illustrates this point. One lux is equal to the light from a candle ten feet away. A standard 100-watt lightbulb shines at 190 lux, while the lighting in an average office building is 300 lux. The body’s clock can be reset by any lights stronger than 180 lux, meaning that the hours you spend in your office directly impact your body’s ability to fall asleep later. That’s because your body reacts to bright light the same way it does to sunshine, sending out signals to try to keep itself awake and delay the nightly maintenance of cleanup and rebuilding of cells that it does while you are asleep. Too much artificial light can stop the body from releasing melatonin, a hormone that helps regulate sleep.

Poor sleep is just one symptom of an unwound body clock. Circadian rhythms are thought to control as many as 15 percent of our genes. When those genes don’t function as they should because of the by-products of artificial light, the effects are a rogue’s gallery of health disorders. Studies have linked depression, cardiovascular disease, diabetes, obesity, and even cancer to overexposure to light at night. Researchers know this, in part, from studying nurses who have spent years working the graveyard shift. One study of 120,000 nurses found that those who worked night shifts were the most likely to develop breast cancer. Another found that nurses who worked at least three night shifts a month for fifteen years had a 35 percent greater chance of developing colon cancer. The increased disease rates could not be explained as a by-product of working in a hospital.

In one of the most intriguing studies, researchers in Israel used satellite photos to chart the level of electric light at night in 147 communities. Then, they placed the satellite photos over maps that showed the distribution of breast cancer cases. Even after controlling for population density, affluence, and other factors that can influence health, there was a significant correlation between exposure to artificial light at night and the number of women who developed the disease. If a woman lived in a place where it was bright enough outside to read a book at midnight, she had a 73 percent higher risk of developing breast cancer than a peer who lived in a neighborhood that remained dark after the sun went down. Researchers think that the increased risk is a result of lower levels of melatonin, which may affect the body’s production of estrogen.

There could be more discoveries on the horizon that show detrimental health effects caused by artificial light. Researchers are interested in how lights have made us less connected to the changing of the seasons. “We’ve deseasonalized ourselves,” Wehr, the sleep researcher, said. “We are living in an experiment that is finding out what happens if you expose humans to constant summer day lengths.”

5. What Should Be Your Sleep Schedule?

In the Canterbury Tales, one of the characters in “The Squire’s Tale” wakes up in the early morning following her “first sleep” and then goes back to bed. A fifteenth-century medical book, meanwhile, advised readers to spend the “first sleep” on the right side and after that to lie on their left. And a scholar in England wrote that the time between the “first sleep” and the “second sleep” was the best time for serious study. Sleep, it seems, wasn’t always the one long block that we consider it today.

This natural mode of sleep sounds weird to the post-Edison world of artificial lights and 6 hour sleep cycles. But it was a fact of life that was once as common as eating breakfast.

For most of human history, every night, people fell asleep not long after the sun went down and stayed that way until sometime after midnight. This was the “first sleep” that kept popping up in the old tales. Once a person woke up, he or she would stay that way for an hour or so before going back to sleep until morning—the so-called second sleep. The time between the two bouts of sleep was a natural and expected part of the night and, depending on your needs, was spent praying, reading, contemplating your dreams, urinating, or having sex. The last one was perhaps the most popular.

Experiments confirm this tendency: Thomas Wehr, who worked for the National Institute of Mental Health in Bethesda, Maryland, was struck by the idea that the ubiquitous artificial light we see every day could have some unknown effect on our sleep habits. On a whim, he deprived subjects of artificial light for up to fourteen hours a day in hopes of re-creating the lighting conditions common to early humans. Without lightbulbs, televisions, or street lamps, the subjects in his study initially did little more at night than sleep. They spent the first few weeks of the experiment like kids in a candy store, making up for all of the lost sleep that had accumulated from staying out late at night or showing up at work early in the morning. After a few weeks, the subjects were better rested than perhaps at any other time in their lives.

That was when the experiment took a strange turn. Soon, the subjects began to stir a little after midnight, lie awake in bed for an hour or so, and then fall back asleep again. It was the same sort of segmented sleep that Ekirch found in the historical records. While sequestered from artificial light, subjects were shedding the sleep habits they had formed over a lifetime. It was as if their bodies were exercising a muscle they never knew they had. The experiment revealed the innate wiring in the brain, unearthed only after the body was sheltered from modern life. Not long after Wehr published a paper about the study, Ekirch contacted him and revealed his own research findings.

Numerous other studies have shown that splitting sleep into two roughly equal halves is something that our bodies will do if we give them a chance. In places of the world where there isn’t artificial light—and all the things that go with it, like computers, movies, and bad reality TV shows—people still sleep this way. In the mid-1960s, anthropologists studying the Tiv culture in central Nigeria found that group members not only practiced segmented sleep, but also used roughly the same terms of first sleep and second sleep.

6. Sleep & Performance

The places where most of the cutting edge research happens and great places to understand the importance of sleep is the Military and Sports fields – areas where human excellence, endurance and performance is pushed to the limits. It stands to reason that these fields notice the effects of sleep problems first. Many sports teams now take great trouble to make sure Light is adjusted to natural cycles, athletes get the full quota of sleep, etc. It s only a matter of time before rest of popular culture catches on – just like many health ides, diets, exercises etc.

7. Sleep Timings Change with Age:

The three basic stages of adulthood—teenage, middle age, old age—have drastically different sleep structures. Teenagers going through puberty find it impossible to fall asleep early and would naturally sleep past ten in the morning if given the choice. Their grandparents often fall asleep early in the night, but then find that they can’t stay that way for more than three or four hours at a time. Middle-aged adults typically fall between the middle of these two extremes, content to fall asleep early when circumstances allow it, yet able to pull an all-nighter when a work project calls for it. These overlapping shifts could be a way to ensure that someone in the family is always awake and keeping watch, or at least close to it. In this ancient system, it makes sense that older adults who are unable to move as fast as the rest of the family are naturally jumpy, never staying in deep sleep for long, simply because they were the most vulnerable to the unknown.

The other stage – babyhood is a time with no sleep structure at all. They sleep and wake up independent of the light/circadian rhythms. To the eternal consternation of all parents!

So human society is biologically designed to live in different time zones?!

Biology’s cruel joke goes something like this: As a teenage body goes through puberty, its circadian rhythm essentially shifts three hours backward. Suddenly, going to bed at nine or ten o’clock at night isn’t just a drag, but close to a biological impossibility. Studies of teenagers around the globe have found that adolescent brains do not start releasing melatonin until around eleven o’clock at night and keep pumping out the hormone well past sunrise. Adults, meanwhile, have little-to-no melatonin in their bodies when they wake up. With all that melatonin surging through their bloodstream, teenagers who are forced to be awake before eight in the morning are often barely alert and want nothing more than to give in to their body’s demands and fall back asleep. Because of the shift in their circadian rhythm, asking a teenager to perform well in a classroom during the early morning is like asking him or her to fly across the country and instantly adjust to the new time zone—and then do the same thing every night, for four years. If professional football players had to do that, they would be lucky to win one game.

8. What Sort of Bed Should You Choose?

The biggest question—whether a bed should be hard or soft—has a long and confusing history. In 2008, the medical journal Spine seemed to settle the question of firmness. It found that there was little difference in back pain between those who slept on hard mattresses and those who slept on softer ones. How hard a person likes his or her bed is a personal preference and nothing more.

In fact, the bed that you find the most comfortable will most likely be the one that you are already sleeping on.

9. Forget The Bed – Sleep Hygiene Is What You Need

While a comfortable mattress may have little impact when it comes to sleep quality, there are several other aspects of the bedroom that do. Taken together, they form what specialists call sleep hygiene. Most are common sense.

– No coffee before bed / in the evening

– Nor is drinking alcohol before bedtime a smart move. Alcohol may help speed the onset of sleep, but it begins to take its toll during the second half of the night. As the body breaks down the liquid, the alcohol in the bloodstream often leads to an increase in the number of times a person briefly wakes up. This continues until the blood alcohol level returns to zero, thereby preventing the body from getting a full, deep, restorative sleep.

– Developing a few habits with the circadian rhythm in mind will most likely make sleep easier. Adequate exposure to natural light, for instance, will help keep the body’s clock in sync with the day-night cycle and prime the brain to increase the level of melatonin in the bloodstream, which will then bring on sleepiness around ten o’clock each night.

– By the same token, bright lights—including the blue-and-white light that comes from a computer monitor or a television screen—can deceive the brain, which registers it as daylight. Lying in bed watching a movie on an iPad may be relaxing, but the constant bright light from the screen can make it more difficult for some people to fall asleep afterward.

– Walk around your house and switch off all bright lights half an hour before you sleep, including the TV, the iPad and the laptop.

– Recent studies have shown that body temperature also plays an outsized role in getting decent sleep. Takes steps to have a comfortable temperature: Take a cold shower, etc.

– Even a small increase in the amount of exercise a person gets leads to measurable improvements in the time that it takes to fall asleep and stay that way. This is particularly true for older adults.

10. The Effort Is Worth Your Time

But, though its effects were subtle, devoting extra time and attention to this most basic of human needs impacted nearly every minute of my day. Because I was improving my sleep, I was improving my life. And all it took was treating sleep with the same respect that I already gave other aspects of my health. Just as I wouldn’t eat a plate of chili-cheese fries every day and expect to continue to fit into my pants, I structured my life around the idea that I couldn’t get only a few hours of sleep and expect to function properly. If there was one thing that I took away from my talks with experts more than any other, it is that getting a good night’s sleep takes work.

And that work is worth it. Health, sex, relationships, creativity, memories—all of these things that make us who we are depend on the hours we spend each night with our heads on the pillow. By ignoring something that every animal requires, we are left turning to pills that we may not need, experiencing health problems that could be tamed, and pushing our children into sleep-deprived lives that make the already tough years of adolescence more difficult. And yet sleep continues to be forgotten, overlooked, and postponed. Any step—whether it comes in the form of exercise, therapy, or simply reading a book like this one—that helps us to realize the importance of sleep inevitably pushes us toward a better, stronger, and more creative life.

Sleep, in short, makes us the people we want to be. All you have to do is close your eyes.

In addition to all the sleep advice, the best part of the book was the full-fledged dissing of poor Freud: Far from being full of hidden symbols, most dreams were remarkably straightforward and predictable. Dream plots were consistent enough that, just by knowing the cast of characters in a dream, scientists could forecast what would happen with surprising accuracy. – “None of Freud’s claims are true by any of our standards today,” Domhoff said, dipping his spoon into his yogurt. “If you look at dreams—if you really look at them like we have—then you see that it’s all there, out in the open. You don’t need any of these symbols.” He went on. “Freudians got all caught up in the idea that there were hidden meanings to our dreams. But their interpretations only worked because we share a system of figurative language and metaphor.”

The Short Summary

Too Lengthy for your tastes? Would reading such a big review eat into your sleep quota for today? Here is a Quick Summary:

1. Sleep for eight hours. Sleep is the natural repair mechanism of the body. If we mess with it, we are bound to have repair related diseases – such as cancer.2. Follow the natural cycle and your circadian Rhythms. Dont live in perpetual jet lag conditions.3. Sleep by around 8-9 and wake up at around 12, go back to sleep by 1 and wake by around 4-5 (add 2 hours if possible on either side)– if you are older, you will need to sleep earlier to be able to fill your quota. it will be almost impossible to sleep late into the day as you age.4. Avoid artificial lights while sleeping, make sure you are exposed to natural light5. Relax yourself before sleep, make sure you get some exercise every day.6. Don’t indulge in dangerous/delicate activities when sleep deprived. Sleep well for high performance.7. Sleep properly to be more healthy in general – it affects all sorts of things in your body.8. Don’t impose your sleep patterns on the rest of your family, esp when they are of another age. Dont impose adult sleep patters on kids.9. Make sure your naps are always 90 minutes or longer. Take naps before important activities, or when stressed.

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